[PATCH 17/22] arm64: dts: qcom: sc7180: Reserve low IOVA range for Venus

[Vikash Garodia]

Venus VPU reserves IOVA addresses below 0x25800000 (600MB), primarily for
secure non-pixel buffers. DMA into that range, from any other stream id
would triggers unhandled SMMU page faults that cause spontaneous device
reboots. This is readily reproduced with one or more browser tabs
driving multiple concurrent video decode streams.

Add a reserved-memory IOVA reservation node covering [0, 0x25800000]
and reference it from the venus node so the IOMMU layer keeps DMA
allocations above that boundary.

Fixes: 058bd0a68950 ("arm64: dts: sc7180: Move venus node to the correct position")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/qcom/sc7180.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index 70fbfb31d4a4dd0d0dd75feb37f686933ff38a14..4ea2dfe3110398ca3ec213301537a734b9cc1eb0 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -692,6 +692,17 @@ rmtfs_mem: memory@94600000 {
 			qcom,client-id = <1>;
 			qcom,vmid = <QCOM_SCM_VMID_MSS_MSA>;
 		};
+
+		/*
+		 * The Venus VPU reserves IOVA below 0x25800000 (600MB),
+		 * primarily for non-pixel buffers using different Stream IDs.
+		 * DMA into that range triggers unhandled SMMU faults and
+		 * spontaneous reboots, so reserve it to keep IOMMU
+		 * allocations above this boundary.
+		 */
+		venus_iova: venus-iova {
+			iommu-addresses = <&venus 0x0 0x0 0x0 0x25800000>;
+		};
 	};
 
 	smem {
@@ -3155,7 +3166,7 @@ venus: video-codec@aa00000 {
 			clock-names = "core", "iface", "bus",
 				      "vcodec0_core", "vcodec0_bus";
 			iommus = <&apps_smmu 0x0c00 0x60>;
-			memory-region = <&venus_mem>;
+			memory-region = <&venus_mem>, <&venus_iova>;
 			interconnects = <&mmss_noc MASTER_VIDEO_P0 0 &mc_virt SLAVE_EBI1 0>,
 					<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_VENUS_CFG 0>;
 			interconnect-names = "video-mem", "cpu-cfg";

-- 
2.34.1